How we change what others think, feel, believe and do
Pleasure in the brain
Pleasure is a sensation that is highly desirable and arguably drives much of our behavior. We seek pleasure and avoid pain.
It is known that there are areas of the brain which, when stimulated, give us these feelings of pleasure.
In the 1960s, researcher Robert Heath found that rats would endlessly press a lever to get electrical stimulation of a part of the brain. He tried it with depressed patients, seeking to obliterate their sadness with physical pleasure. It worked, but only as long as the stimulation was present.
Since Heath's experiments, the neurotransmitter dopamine in the brain has been found to be a key method by which these good feelings are activated.
The dopamine pathways have also been identified as the areas where pleasure seems to be stimulated and indeed these areas are active when you are enjoying pretty much anything. Narcotic drugs result in increased dopamine flows. So also does eating good food and listening to nice music.
More recent experiments by Kent Berridge have indicated that dopamine does not directly create pure pleasure, but rather is more to do with desire and wanting which, although pleasurable are not the undirected pleasure of satisfaction and closure.
It seems that opioids and opiates are responsible for causing sensations of pleasure and liking. This is confirmed by results such as where naloxone, an opiate inhibitor, makes food less pleasant-tasting whilst it does not make people less hungry.
This fits with addiction, where addicts are more driven by desire than pleasure.
Opiates affect many parts of the brain, with particular overlap of the dopamine system, which perhaps accounts for some of the confusion.
Oxford neuroscientist Edmund Rolls has noted that neurons in the orbito-frontal cortex (OFC) area of the forebrain, behind the eyes, and particularly near its surface are also implicated in pleasure. Interestingly, different cells have different associations -- some with with sweet taste, others with money and so on.
Phillips, H. (2003) The pleasure seekers, New Scientist, 11 Oct. 2003, pp. 36–40